Additional File 3

Title: Review Table of proposed mediators and physical activity behaviour

Authors / Participants / Intervention / Constructs measured / PA measure / Behaviour Change / Action Theory Test / Conceptual Theory Test / Mediated Effect / Quality of studies /11
Ash et al. (2006) / 176 adults with BMI >27 kg/m2 / RCT, 12 months, real practice setting
3 arms: 1st-group based CBT lifestyle diet and exercise sessions; 2nd-individualised dietetic treatment; control-nutrition resource booklet / self-efficacy / IPAQ / Non significant (ns) and trivial effect size (ES) / Generalized Self-efficacy
(between intervention groups and control) at 3 months and 12 months
ES=small / Not stated / Not stated / 6
Bennet et al. (2008) / 72 inactive adults / RCT, 6 months, rural home setting, 2 arms: int. group-motivational interviewing phone calls; control-phone calls with no MI content / self-efficacy / CHAMPS physical activity questionnaire for older adults / No (ns) and trivial ES / Self-efficacy
ES=medium / Not stated / Not stated / 5
Bock et al. (2001) / 150 sedentary adults / RCT, 6 months, 2 arms: int. group-individualized motivationally tailored print materials; control-standard exercise promotion print materials
Assessment at 12 month follow-up / TTM
perceived barriers and benefits, self-efficacy, processes of change / 7Day PAR / No (ns) and trivial ES / No (ns) / Self-efficacy, barriers, and behavioural processes sig / Not stated / 6
Cardinal & Spaziani (2007) / 109 University students / Quasi-experimental design, 10 weeks, 3 arms: 1st lifestyle class, 2nd online lifestyle class, 3rd control classes / TTM
perceived barriers and benefits, self-efficacy, processes of change / GLTEQ / No (ns) / No (ns) / Not stated / Not stated / 4
Cerin et al. (2006) / 52 inactive adults / RCT, 16 weeks, 2 arms: 1st group-print only; 2nd group-print plus telephone calls to encourage/assess progress. Assessment at 16 weeks and 4 week follow-up / Social support / CHAMPS / Yes – sig change at 16 weeks (small ES). NS difference at follow-up and trivial ES / Social support at 16 weeks
(ES=small) but not at follow-up / Yes – change at 16 weeks (small ES). No (ns) difference at follow-up and trivial ES / Social support was a mediator at 16 weeks. (small ES) / 8
Cramp & Brawley (2006) / 57 post natal women / RCT, 4 weeks, 2 arms: 1st group-standard exercise; 2nd group-mediated by group cognitive behavioural counselling. Assessment at 4 weeks and 4 week follow-up / SCT
Outcome Expectations,
Barrier Self-efficacy / PAR / Yes – sig change at 4 and 8 weeks in favour of the group-mediated intervention (large ES) / Yes – change in outcome expectations and barrier self-efficacy were sig higher in the group mediated intervention (large ES) / Not stated / Not stated / 5
Dallow & Anderson (2003) / 58 sedentary obese women / RCT, 48 weeks, 2 arms: int. group-theory based lifestyle group sessions; control-free access to fitness facility. Assessments at 24 and 48 weeks. / TTM
Processes of change, self-efficacy / 7 Day PAR / Yes - sig difference for lifestyle at 24 weeks
(ES=medium) and 48 weeks (ES = large). / -self-reevaluation and environmental reevalaution were sig higher in lifestyle group at 24 weeks (medium ES). NS differences at 48 weeks. / Not stated / Not stated / 5
Dinger et al. (2007) / 56
insufficiently active women / 2 group experimental, 6 weeks, both groups received pedometers, step logs, print, weekly emails; one group also received emails based on TTM constructs / TTM
Processes of change, decisional balance, self-efficacy / IPAQ / No (ns) / No (ns) / Not stated / Not stated / 5
Elbel et al. (2003) / 120 skilled labour employees / Quasi experimental at 3 work sites, 4 weeks. 1st site professional education sessions based on TTM/SCT, 2nd site peer-led education sessions based on TTM, 3rd site control. Assessments post-test and 4 weeks follow-up. / Self-efficacy / PAR / No (ns) / No (ns) / Not stated / Not stated / 4
Fahrenwald et al. (2004, 2005) / 44 sedentary mothers with children / RCT, 10 weeks, WIC setting, 2 arms: int. group-counselling and biweekly phone calls focusing on PA; control-counselling and phone calls focusing on self-breast examination / TTM
decisional balance, self-efficacy, self-liberation, counterconditioning, environmental reevalaution, social support (SS) / 7 Day PAR / Yes
ES=large / All constructs sig / All constructs sig / Test did not support mediation / 7
1. Fortier et al. (2007)
2. Blanchard et al. (2007) / 120 inactive adults / RCT, 13 weeks, primary care practice setting, 2 arms: int. group-counselling from HCP plus intensive autonomy support PA counselling; control-counselling from HCP / 1.SDT
autonomy support, autonomy, perceived competence
2. barrier self-efficacy, task self-efficacy / GLTEQ / Yes
ES=large / 1. autonomy support
-autonomous motivation ES=small
Perceived competence was NS
2. task self-efficacy and barrier self-efficacy (ES = medium) / 1. Autonomy support sig but not autonomous motivation or competence2. task and barrier self efficacy were sig / 1.Not stated
2. task self-efficacy was a sig partial mediator (small ES); barrier efficacy was a sig mediator but trivial ES / 8
Gallagher et al. (2006) / 165 overweight women / RCT, 6 months, home setting, 4 arms: all groups received weekly sessions; assigned to 1000 kcal/wk at MPA; 1000 kcal/wk at VPA; 2000 kcal/wk at MPA; 2000 kcal/wk at VPA / TTM
self-efficacy,
decisional balance, expected outcomes and barriers, processes of change / 7 Day PAR / No (ns) / No (ns) / Sig for self-efficacy, decisional balance, processes of change / Not stated / 6
Hallam & Petosa (2004) / 82 adult employees / non-equivalent pre-post test repeated measures, 12 months, workplace setting, 2 arms: int. group-counselling sessions plus access to on-site fitness facility; control-new members of fitness center / SCT
outcome expectancy, self-regulation, self-efficacy / 7 Day recall / No (ns) difference at 6 weeks, 6 months, but sig at 12 months / -self-regulation (ES=large)
-outcome expectancy (ES=small)
No (ns) difference in self-efficacy / Not stated / Possible mediation found for self-regulation at 12 months, not found for outcome expectancy / 5
Hurling et al. (2007) / 77 adults / stratified control trial, 9 weeks, 2 arms: int. group-internet based behaviour change system, with email or mobile phone reminders; control-verbal advice on PA only / perceived control, intention/motivational change – all created for this study / IPAQ and blue
tooth accelerometer / Yes - sig differences between groups on both measures / Sig differences perceived control
intention
internal control/external control (instruments created for study) but not motivational change (instrument created for study) / Not stated / Not stated / 6
Jacobs et al. (2004) / 511 low income women / Non-random assignment , 1 year, 2 arms: 1st group intensive counselling and computer intervention based on TTM and SCT, 2nd group minimal health advice standard. / Self-efficacy, perceived barriers, social support / Questionnaire created for the study / No (ns) / No (ns) / No (ns) / Not stated / 4
Jones et al. (2004) / 450 psychology students / RCT, 2 weeks, university setting, 6 arms: participants received positively or negatively framed pamphlets and were told materials were from 1) credible source, 2) non credible source, 3) no source reported / TPB
behavioural beliefs, exercise attitudes, subjective norm, perceived behavioural control, exercise intention / GLTEQ / No (ns) / No (ns) differences for any TPB variable / Not stated / Not stated / 6
Kinmonth et al. (2008) / 365 sedentary adults / RCT, 1 year, GP setting, 3 arms: 1st theory-based behaviour change program at home, 2nd theory based program by phone, 3rd was a control group given a brief advice leaflet. / Intention / Heart Rate, corroborated by Vo2 max testing; EPIC Norfolk physical activity questionnaire / No (ns) and trivial ES / Change in intention in favour of the intervention groups at six months (medium ES) but no (ns) difference at one year. / Not stated / Not conducted / 7
Kloek et al. (2006) / 1926 adults / Quasi-experimental, 2 year, community setting, 2 arms: int. communities-given action plans related to determinants of health, courses, and special events; control-comparison communities / Unspecified theory
-attitude, self-efficacy, / SQUASH / No (ns) / No (ns) / Not stated / Not stated / 3
Levy & Cardinal (2004) / 126 sedentary adults with intention of starting an exercise program / RCT, 2 months, community setting, 3 arms: 1st int. group-mail delivered packet promoting SDT constructs; 2nd int. group-packet plus booster postcard; control-PA facts booklet / SDT
perceptions of autonomy, perceptions of competence, perceptions of relatedness, behavioural regulation / Leisure Time Exercise Questionnaire / No (ns) / No (ns) / Not stated / Not conducted because of the null effects / 6
Lewis et al. (2006) / 150 sedentary adults / RCT, 6 months, 1st group received motivationally tailored intervention, 2nd group received generalized exercise intervention. Assessments at 1,3, and 6 months. / TTM
Processes of change, self-efficacy, decisional balance / PAR / Yes – sig difference in favour of motivationally tailored group (small ES) / Significant effect on behavioural processes (small ES) but not on Cognitive processes, self-efficacy, decisional balance / Sig effect on self-efficacy and behavioural processes but ns for cognitive processes and decisional balance / Behavioural processes of change did not act as a sig mediator / 9
Little et al. (2004) / 151 sedentary adults / RCT, 1 month, practice setting, 8 arms: 1st int. group-Health Education Authority booklet; 2nd int. group-counselling sessions; 3rd int. group-exercise prescription by GP. Participants could received no int., a single int., or a combination of all 3 / unspecified theory
-stage of change,
intention, perceived behavioural control, attitude, attitude of important others, attitude of important others to practical help / GLTEQ / Yes – sig only in most intensive group-counselling plus exercise prescription / Intention different among groups for those with low intention at baseline.[1-6] / Intention was related to behaviour / Not stated / 3
Milne et al. (2002) / 248 undergraduate students / Post-test design, 2 weeks, university setting, 3 arms: 1st int. group-motivational leaflet; 2nd int. group-motivational leaflet plus volitional int.; control-neither, read 3 paragraphs of a novel / PMT
perceived severity, perceived vulnerability, response efficacy, self-efficacy, response costs / PA questionnaire, number of 20 minute sessions in past week / Yes - sig group 2 increased PA compared to group 1 and control
ES=medium / Yes – sig differences between int. groups and control for perceived vulnerability, perceived severity of premature death, perceived severity of pain, fear, response efficacy, self-efficacy, response costs, intention / Not stated / Not stated / 5
Napolitano et al. (2008) / 239 inactive adults / RCT, 6 months, 3 arms: 1st print-based motivationally tailored, 2nd telephone-based motivationally tailored, 3rd contact control. Assessments at 6 mos and 12 mos follow-up. / TTM
Processes of change, self-efficacy, decisional balance / PAR / Yes –both intervention groups positively changed physical activity (medium ES) / All constructs (medium to large ES) / Behavioural processes were sig all other variables were ns / Processes (behavioural) were supported as as a mediator. Cognitive processes acted as a suppressor. / 8
Parrott et al. (2008) / 170 sedentary college students / Randomized groups pre-post test, 2 weeks, university setting, 3 arms: 1st int. group-positively framed emails; 2nd int. group-negatively framed emails; control-no emails / TPB
attitude, intention,
subjective norm, perceived behavioural control / GLTEQ / Yes-Positively framed sig different than control group. / Yes - intention (positively and negatively framed higher than control group)
-affective attitude (positively and negatively framed higher than control group when baseline was not low)
-perceived behavioural control(positively and negatively framed higher than control group) . No (ns) for Instrumental attitude and subjective norm / Not tested / Not stated / 6
Plotnikoff et al. (2005) / 2121 employees / pre-post test design, 12 weeks, workplace setting, 2 arms: int. group-weekly email message; control-no email / TTM, PMT
self-efficacy, pros and cons, severity, intention / GLTEQ / Yes- sig difference between groups but trivial effect size / No (ns) / Not stated / Not stated / 6
Reger et al. (2002) / 31,420 sedentary adults aged 50-65 / Quasi-experimental 8wk community study, target community received paid media and public relations communications for walking, control community no communication / TPB
Attitude, subjective norm, PBC, intention / Observation and self-report measure / No (ns) and trivial effect size / No (ns) for attitude or subjective norm. Sig differences in intention and PBC but trivial effect sizes / Not stated / Not stated / 5
Rovniak et al. (2005) / 50 sedentary women / RCT, 12 weeks, 2 arms: 1st int. group-high theoretical fidelity email messages; 2nd int. group-low theoretical fidelity email messages. Included a 1 yr follow-up. / SCT
self-efficacy, outcome expectations, enjoyment, goal setting and planning, social support / self-report logs and questionnaire / No (ns) at 12 weeks and 1 yr and trivial effect size / Yes- sig for goal setting (ES=med), positive outcome expectation (ES=med) / Not stated / Not stated / 6